Valve control unit



March 21, 1939. ACKER 2,151,493

VALVE C ONTROL UN I T Filed March 10, 1937 2 Sheets-Sheet l QHHHMNW 9 Z-INVENTOR.

ATTORNEY;

March 21, 1939'. G. H. ACKER VALVE CONTROL UNIT ,2 Sheets-Sheet 2 FiledMarch 10, 1937 INVENTOR. @eorge 7% 06%61 BY n W {7W (77 ATTo'RNEYs,

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Patented Manfil, 1939 UNITED STATE VALVE NTROL UNIT George H. Acker,Shaker Heights, Ohio, assignor to The Cleveland Worm & Gear Company,Cleveland, Ohio, a corporation of Ohio Application March 10,

Claims.

The present invention relates to a power driven mechanism for operatingvalves wherein the opening and closing action of the valve element, suchas a gate or a disc, is dependent upon the movement of a valve stem.

A valve control unit of the character to which my invention pertainsconsists essentially of a drive motor, a reduction gear train andelectric control switches actuated by forces .and movements of the geartrain,.and adapted to start and stop the drive motor. The driven shaftof the gear train of such a unit is so connected to the 'valve stem thatits rotation is effective to produce opening and closing movement of thevalve stem As the valve element such as the ggte or disc approaches itsclosed position in the v very rapidly, and its amount of furthermovement is very slight, which means that the power driven valve controlunit must be capable of delivering excess torque and then stoppingimmediately upon the valve closing stroke. Since the moving parts of apower source, such as the shaft and armature of an electric motordevelop a substantial kinetic energy during operation, and even aftercessation of actuation of such a motor, this kinetic energy must stillbe absorbed by the other elements of the valve control unit such as thevalve, the valve stem, and the reduction gear train.

It is therefore the general object and nature of my invention to providemeans for automatically disconnecting the drive motor from the remainderof the mechanism when the valve has reached its proper seated or closedposition, so that the kinetic energy of the drive motor will not beapplied to the remainder of the mechanism, but can be freely dissipated.

My invention also provides means for insuring the delivery of requiredtorque to the valve operating element during the final stage of thevalve closing stroke so as to insure a proper seating of the valve.

To the accomplishment of the foregoing and related ends, said invention,then, consists of the means hereinafter fully described and particularlypointed out in the claims.

The annexed drawings and the following description setforth in detailcertain mechanism embodying the. invention, such disclosed meansconstituting, however, but one of various mechanical forms in which theprinciple of the invention may be used.

In said annexeddrawings: Fig.1 is a sectional view of a valve controlunit ve seat, its resistance to movement increases 1937, Serial No.1363.141

embodying the principle of my invention, such section being takensubstantially in the plane of the reduction gear drive shaft; Fig. 2 isa view of the control switch compartment of the valve control unit, andwith the cover plate removed; Fig. 3 is a sectional view of the unittaken substantially upon a plane normal to that of Fig. 1 and along line3--3 thereof; and Fig. 4 is a sectional view, also taken upon a planenormal to that of Fig. l and substantially along line 4-4 thereof.

Now referring more particularly to the drawings, the device showntherein includesa housing 1, one end of which is closed by an adapterplate 2 having an external face upon which the drive motor (not shown)is mounted. A worm shaft 3 carrying the worm 4 is journalled in thehousing I by the bearings 5 and 6. The worm 4 is axially slidable bymeans of a spllnecl connection with the shaft 3 in order to produce ahammer blow effect in the operation of the valve control unit. Thislatter feature is not claimed as a part of the present invention, sinceit is more fully set forth, particularly pointed out, and distinctlyclaimed in my co -pending application Serial No. 123,735, filed Feb. 2,1937.

2 A worm wheel 1 keyed to the shaft 8 is driven by the worm 4. The shaft8 has an exteriorly projecting portion 9 which can be directly connectedto a valve stem or indirectly connected to a valve stem nut by means ofspur gearing, such nut being carried by the valve yoke. Such lattertypes of connections are well known in the art and hence are not hereillustrated or further described.

A helical gear III is mounted on the right hand end of the worm shaft 3,as shown in Fig. 1. The gear 10 meshes with another helical gear llcarried by the drive shaft l2, and is connected thereto through ahelical spline l3. The shaft I2 is iournalled at one end in the bearingl4 and its other end is keyed to the coupling sleeve l5 journalled inthe bearing l6 mounted in the adapter plate 2. The motorshaft of thedrive motor is connected in the outer end. of the sleeve IS. The helicalspline l3 has an enlarged portion I! which forms a shoulder for theabutment of the end of thegearIL v 1 The arms of a fork or yoke I8 bearagainst the other end of the gear II and normallyhold'it' in theposition abuttingagainst the shoulder onthe helical spline l3. 1 a

The yoke I8 is mounted upon a rock shaft l9 which extends into thecontrol switch compartment of the housing I., An arm 20 is mounted onthe end'of the shaft. l9 and carries-the camll.

The cam II is adjustable to various positions of eccentricity withrespect to the arm by means of the clamping stud 22. The cam 2| engageswith the end of the plunger 23 which passes through the limit switch 24and carries a flange 23 against which the compression spring 26 abuts.The other end of the compression spring 28 is mounted within an annularboss 21 in the housing I, and bears against the threadedadjusting screw23.

The worm shaft 3, extends to the exterior of the housing I and carrieson its outer end a hub 33 to which the hand wheel 3i is keyed, asindicated at 32. A flange 33 on the inner end of the hub 30 abutsagainst an inwardly directed flange 33 on the. cup shaped member 35which is attached to the housing l-. The hub 30 has a pair of slots 33for' the reception of the cross pin 31 carried by the outer end of theshaft 3. A compression spring 38 is mounted between the hub 33 and thehousing I. The hand wheel 3i can thus be connected to the worm shaft 3by merely pushing it axially inward against the pressure of the spring33, so that the pin 31 is engaged in the slots 33. The hand wheel SI ofcourse is provided for emergency, manual opera-' tion of the valvecontrol unit.

A control switch drive shaft 40 extends from the inner end of the driveshaft 8 into the control switch compartment, and carries a pinion lladapted to be connected in customary manner to the limit switch 42.shown in Fig. 3, a cover plate 33 is provided forthe control switchcompartment of the housing i.

The operation of the above described device is as follows: v

Gear ii is normally connected with the helical spline i3 on the driveshaft l2, as shown in Fig. 1. Assuming that the valve is in openposition and that it is to be moved to closed position by rotation ofthe drive shaft i2, in a direction indicated by the arrow in Fig. 1, orin a counterclockwise direction with respect to Fig. 4, the gear II willhave a tendency to back off'the splines i3, but this tendency isresisted by the arms of the yoke it. The hand of the helix on the gearii is the same as the hand of the helix of the splines i3, so that thehelical teeth on the gears l3 and II are so disposed as to assist thetendency of the gear Ii to move in a right hand direction along theshaft l2 and to back off from the splines I3. As the valve approachesclosed or seated position, its increased resistance to movement is ofcourse transmitted through the shaft 3, the worm gear I, the worm 4, theshaft 3, the gear II to the gear ii with theresultant increase in theforce with which the gear I I tends to move against the arms of the yokel3 and incidentally against the pressure of the spring 23. As soon asthis resistance is built up to a predetermined value, which is of coursethe force necessary to produce complete seating of the valve, themeasure of the spring 23 will be overcome and therefore the gear ii willmove to a position out of engagement with the splines II. The yoke II,the arm 23 and the cam 2i will of course then assume a position asdicated by the dotted lines in-Figs. l and 2. ment of the parts willmove the plunger 23 to such a position as to open the contacts in theswitch 24 and thereby deenergize the drive motor. The kinetic energy, orthe inertia of the armature and shaft of the drive motor will then befreely dissipated by rotation of the shaft i2, since the gear Ii hasbeen disconnected.

uch move-- it will be seen that the splines l3 are of limited length,that is, not as long as the teeth of the gear ll, so that the latter canmove to disconnected position with respect to the splines l3 withoutlosing mesh or becoming disengaged with the teeth of the gear in.

When the drive shaft i2 is rotated in an opposite direction, or in acounter-clockwise direction. with respect to Fig. 4, for the purpose ofagain opening the valve, the splines i3 will quickly reengage with thegear Hand the latter will return to its normal position as shown inFig. 1. The valve opening operation or stroke of the control unit is ofcourse controlled through the switch 32, so that the drive motor isstopped as the valve approaches fully opened position.

It will thus be seen that my above described invention not only providesmeans for insuring the seating of the valve under a sufficient pressure,but also disconnects the drive motor after such seating has beenobtained, to permit the free rotation of the motor and the dissipationof its kinetic energy so that such energy need not be absorbed throughimpact resilience of the valve parts and of the gear train.

Other modes of applying the principles of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a valve control unit, the combination of power driving means, arotatable shaft adapted to move the valve to open and closed positions,a reduction gear train connected to said shaft, an axially slidable,helically splined coupling connecting said driving means to said geartrain, the length of the spline on said coupling being shorter than theaxial movement thereof whereby said spline is movable to disengagedposition accordingly to disconnect said driving means.

, 2. In a valve control unit, the combination of power driving means, arotatable shaft adapted to move the valve to open and closed positions,a reduction gear train connected to said shaft, an axially slidable,helically splined coupling connecting said driving means to said geartrain, the length of the spline on said coupling being shorter thantheaxial-movement thereof whereby said spline is movable to disengagedposition accordingly to disconnect said driving means, and

yieldable means for resisting the axial movement of said coupling.

3. In a valve control unit, the combination of power driving means, arotatable shaft adapted to move the valve to open and closed positions,a reduction gear train connected to said shaft, an axially slidable,helically splined coupling connecting said driving means to said geartrain, the length of the spline on said coupling being shorter than theaxial movement thereof whereby said spline is movableto disengagedposition accordingly to disconnect said driving means, yieldable meansfor resisting the axial movement of said coupling, and control meansactuated by axial movement of said coupling for deenergizing, saiddriving means when the latter is disconnected.

4. In a valve control unit, the combination of power driving means, arotatable shaft adapted to move the valve to open and closed positions,a reduction gear train connected to said shaft, an axially slidable,helically splined coupling connecting said driving means to said geartrain, and a helical gear carried by said coupling and engaging at alltimes with a helical gear in said gear train, the hand of the helix insaid firstnamed helical gear being of the same hand as the helix of thespline of said coupling.

5. In a valve control unit, the combination of power driving means, arotatable shaft adapted to move the valve to open and closed positions,

10 a reduction gear train connected to said shaft,

an axially slidable, helically splined coupling connecting said drivingmeans to said gear train, a helical gear carried by said coupling andengaging at all times with a helical gear in said gear train, the handof the helix in said first-named helical gear being of the same hand asthe helix of the spline of said coupling, and adjustable spring pressuremeans for resisting the axial movement of said coupling.

GEORGE H. ACKER.

